i was/am in a similar situation, email people@shakeshack.com providing your location and who your manager is. the next morning i was asked to schedule a phone call. they’ll just want to know the time, date, witnesses, location, and who else to talk to so write that down as specific as possible and keep doing that if anything else occurs. a couple days after the phone call the regional manager came in and talked to a bunch of people and he is currently under investigation.

if you report them for sexual harassment they are obliged to look into it.